1. Field of the Invention
The invention relates to refuse collection vehicles, particularly refuse collection vehicles equipped with pendular packing devices capable of ejecting stored refuse from the rear of the vehicle body.
2. Description of the Prior Art
Refuse collection vehicles normally have a vehicle chassis consisting of a frame with front and rear sets of wheels, a cab for housing the vehicle operator, and an engine for powering the vehicle's hydraulic system and rear wheels. The cab is mounted atop the frame at the front end and a vehicle body is located rearward of the cab and longitudinally aligned with the frame.
The vehicle body has a receiving hopper into which refuse is deposited. The receiving hopper has a partition separating it from a storage compartment immediately rearward of the receiving hopper. The storage compartment normally includes a roof, two sides, a floor, and at least one rear door that may be opened to permit egress of stored refuse. The partition includes an aperture for passage of refuse from the receiving hopper to the storage compartment.
Refuse may be transferred through the aperture in at least two ways. One way is by longitudinally sliding a packing device positioned at the front of the receiving hopper towards the rear of the vehicle so that a refuse engaging face of the packing device pushes the refuse through the aperture into the storage compartment. Another way is by using a pendular packing device pivotally mounted within the receiving hopper that arcuately swings from a raised position to a lower position towards the rear of the receiving hopper. The receiving hopper floor is normally curved to correspond to the arc of the pendular packing device and a refuse engaging face of the packing device transfers the refuse through the aperture. Since the transfer of refuse is aided by gravity and since this type of packing device is typically equipped with low-volume, fast-acting hydraulic cylinders, refuse can be transferred to the storage compartment at a faster rate than with a conventional sliding packing device, which usually increases the overall efficiency of refuse collection. Also, sliding packing devices have load bearing surfaces in contact with one another that are prone to wear and accordingly have increased maintenance cost as compared with pendular packing devices.
To empty waste from the storage compartment, for example at a landfill site, refuse collection vehicles are typically equipped with a vehicle body tilting mechanism. The vehicle body is normally attached to the rear of the vehicle frame by means of a hinge and a hydraulic lifting cylinder is provided to raise the front end of the vehicle body. Refuse is then permitted to downwardly slide from the storage compartment through the open rear door. Raising the vehicle body places the vehicle in a precarious and unsafe position, especially on the uneven terrain frequently encountered at a landfill site. Also, there is a risk of contact with overhead obstacles, such as electrical wires. The lifting cylinder is expensive and it is time consuming to raise the vehicle body.
To address these concerns, some refuse collection vehicles have recently been equipped with refuse ejection systems. The refuse ejection system employs a sliding packing device typically powered by a pair of telescoping hydraulic cylinders. To eject the refuse, the telescoping cylinders extend the packing device, which engages the rear partition of the receiving hopper and longitudinally slides the partition towards the rear of the vehicle. Refuse is thereby displaced out through the open rear door, obviating the need for the vehicle body tilting mechanism.
Conventional refuse ejection systems employ the sliding packing device, with the inherent wear problems previously described. In addition, a pair of telescoping cylinders is typically provided, which increases vehicle cost and maintenance. Due primarily to their large volume, telescoping cylinders are inherently slow acting as compared with low volume cylinders, exacerbating the problem of slow transfer of refuse from the receiving hopper to the storage compartment normally experienced with sliding packing devices.
To increase collection efficiency, refuse vehicles are sometimes equipped with automated container loaders for depositing refuse within the vehicle body. Though these devices may increase the rate at which individual containers may be loaded, the overall collection efficiency is often limited by how quickly the deposited refuse can be transferred from the receiving hopper to the storage compartment.
The present invention seeks to overcome the disadvantages of sliding packing devices and vehicle body tilting mechanisms by providing a low cost, minimal maintenance system for rapidly transferring refuse from the receiving hopper to the storage compartment of a refuse collection vehicle that may be advantageously employed in conjunction with an automated container loader to increase the overall efficiency of refuse collection.